Safecracker

Safecracker backbox. The token mechanism is at the bottom of the picture.

Safecracker backbox. The backbox houses a board game and the token deliver mechanism. The ropelight uses flasher circuits. The board game has an entire circuit board of its own, and is separate from the lamp matrix.
Safecracker has more controlled lights than any other pinball machine. It also uses pretty much every solenoid, flasher and flipper circuit.

Middle of the game. The playfield runners are long, thick steel. Makes the playfield very, very heavy. So much so that it seems to be stuck the first time you try to lift it.

Token release mechanism

Some of the backbox lamp circuitry. It is powered off of the 6.3V winding. It uses a half-wave rectifier. The lamps are drive through transistors and a big shift register circuit - similar to the Whitewater topper and the AfM saucer.

Lower half of the machine. This is jammed with stuff., Safecracker has 4 drop target banks, two kickbacks (one on a ramp), three flippers, a multi-hit target (like a poor man's inline drop) with a subway, one upkicker, two reed switches in the top lanes, a saucer, a scoop with kickout, a ramp ball lock, and a playfield spinner.

The coin door board. Note the extra connectors and wiring for the token-sensing coin door. I think that's the mod for the US coin doors.

Here's the bowing problem with the Safecracker playfield. Actually, it is more like a break. The playfield is straight up to the end of the stiffener (the black strip in front of the post and long rubber).
The wood is weakened by the routing for the tee nut. And in this case, the post has been overtightened. The playfield bends away at an angle from this point.

Note the broken outer layers in the plywood. This break dramatically reduces the stiffness of the playfield.

Now, here's the tricky part. the two holes that you see on either side of the post breakpoint are tee nuts inserted into the top side of the playfield. Something was supposed to screw in there. They are a good place to start for reinforcements; reaching down to the other post might do the trick.